1. Field of the Invention
The present invention relates to the transfer of previously aligned abutting articles between work stations without disrupting the alignment and particularly to the feeding of book blocks to a binding machine. More specifically, this invention is directed to devices for transferring pre-aligned multi-layer articles, book blocks for example, between work stations located at two different vertical levels while maintaining the alignment of the layers. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly well-suited for feeding book blocks along an upwardly inclined transfer path to the block clamps of a binding machine, particularly a machine for securing the layers together by means of an adhesive or adhesively coated tape. A book block is comprised of a plurality of loose layers or sheets and, prior to binding, these sheets are brought into alignment. In a book manufacturing machine the book blocks must be transferred along an upwardly inclined path to a plane wherein they will be engaged by the block clamps of the binding apparatus. Prior art devices for feeding book blocks along the inclined path to the block clamps have proven to be unsatisfactory since they have subjected the blocks to a tilting force which has resulted in the relative displacement of the prealigned loose block components. Accordingly, it is standard practice in the prior art to subject the book blocks to a further aligning operation subsequent to their transfer to the level at which they are engaged by the block clamps. This aligning operation downstream of the transfer to the block clamp level occurs on what is known in the art as the "jogging path" of the binding machine. The necessity of providing such a "jogging path" significantly increases the cost of the book making apparatus since it necessitates the addition of at least two sets of block clamps on both the introduction and opposite sides of the conveying system.